


Human Subject #1

by RedAlaina



Category: Undertale (Video Game)
Genre: Experiment, F/M, Gaster - Freeform, Oneshot, Smut, definitelysmut, gastersinning, itsforresearch, preundertale, sinning, skelesmut, unnamedfemale
Language: English
Status: Completed
Published: 2016-04-01
Updated: 2016-04-01
Packaged: 2018-05-30 13:25:45
Rating: Mature
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 6,144
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/6425746
Author URL: https://archiveofourown.org/users/RedAlaina/pseuds/RedAlaina
Summary: <blockquote class="userstuff">
              <p>Dr. W.D. Gaster has waited for this opportunity for too long. A human...fallen to the underground? ...This rare opportunity could not be passed by. </p>
<p>Unnamed human female x Gaster</p>
<p>Also either I'm stupid or something because I tried to space this properly several times but it refused to comply and I'm tired of fiddling with it. So sorry if it seems smooshed. Ugh.</p>
            </blockquote>





	Human Subject #1

**Author's Note:**

  * Inspired by [For Research (W.D. Gaster/Reader)](https://archiveofourown.org/works/6416041) by [EsperAqua](https://archiveofourown.org/users/EsperAqua/pseuds/EsperAqua). 



> YO THIS ISN'T MY CONCEPT a friend of mine wrote it out first and I was just desperate to put my own spin on it, it was tons of fun, yeah. 
> 
> Check her out she's super cool.

The lab was quiet.  
This was normal.  
The cool, sterile air settled around Gasters bones with calming familiarity. He sat at his desk, calmly, shuffling papers with keen interest. His research notes had hit a stopping point, and he was sorely disappointed about it. He flipped through the papers again, noting solemnly that there really wasn't more to do. His research had come to an abrupt halt, his resources for knowledge and information completely exhausted.  
If only he could get his hands on a human...  
He sighed deeply, knowing full well that the likelihood of that happening was minimal, especially in any sort of time frame that would calm his eager, jittering nerves to study, to learn.  
Time passed.  
Slowly.  
Frustratingly.  
And then, finally, a glimmer of hope.  
A human had been spotted. 

Gaster frowned in slight disapproval as the snow crunched beneath his feet. The boots were doing their job of keeping the damp out, but it was not a comfortable feeling for him nonetheless. He was not used to leaving confines of Hotland, where his lab resigned, and the dramatic scenery change affected him more than he cared to admit. A calm, logical type. He nodded in approval of himself. Yes, that's the feeling he always liked. It was just rattling him because it was such a sudden change. As soon as he figured out the problem his jittery nerves calmed, and he glanced around the whiteness. A human, spotted in Snowdin? It didn't really seem possible, but it was too much of a rare opportunity to not investigate. He pressed his bony chin further into his thick turtleneck, moving forward. The town glowed warmly, and smaller monsters, mostly children, ran and played in the white fluff as adults watched, amused. After talking to a nice enough shopkeeper, he learned the general direction of the sighting, and sighed as the rabbit pointed towards the wooded area beyond town.  
If a human really was there, it would be worth it.  
Face set in stone, he rounded the woods, walking for an hour...two hours...three? He called out, offering aid and help to any lost souls in need of shelter from the cold.  
"H-h-hello-o?"  
He froze in place, blinking once at the unexpected response. "Ah - yes? Hello? Is someone there?" He tried to keep his excitement in check, but wildly spun, looking for any signs of movement among the trees and ice.  
"Hngh-!" The voice drew back, making a panicked noise and Gaster spun in the direction of the sound.  
"It's all right, it's all right!" He insisted in a cool, calm tone. "I'm here to help."  
Slowly, from behind a dense section of trees and shrubbery, a pale, fleshy flace poked out from behind a especially thick trunk. Gaster held his breath in awe. "Wh-who - ?" Their lips jittered with a jolt, an uncrontrollable shiver overtaking their body.  
"Ah - " He let out the breath, careful to be as calm as possible. "My name is Gaster. I...I don't want to hurt you." He continued, gesturing in welcoming hand motions. "We should try to get you someplace warm?" He offered carefully.  
The human was hesitant. He couldn't exactly blame them, it wasn't the surface after all, and there was a clear difference in appearance that was possibly alarming. Still, the fleshy face returned, this time emerging from behind the wooded area. Their feet shuffled together, whether from nervousness or the cold he couldn't tell. The long pants they were wearing were half-soaked and clung to the skin underneath. They buried their face in a red scarf and fur-lined blue jacket desperately, trying anything to block out the biting cold from the air.  
Gaster noted that their eyes were squinted, and he realized they may be having a difficult time seeing for some reason.  
"Are you all right? Can you wa-?" He didn't get to finish the question as the human stumbled forward, seemingly tangled in their own limbs and promptly passed out mid-step.  
Gaster scrambled to catch them, their weight making his bones creak ever so slighly. "My word." He breathed, suddenly very concerned about the state of the 'specimen'. It was a ways back to the lab, but it would have to be done. Inhaling deeply, he called upon his powers, feeling the blue and orange magic tingle in his sockets, and six disembodied hands similar to his own appeared from thin air, helping him carry the cumbersome human. He cast a worried downward glance on them. Priority one was to get back to the lab and get them in working order. 

Something was definitely wrong.  
Gaster rubbed his thumbs against his forefingers with a bony scraping, pacing the room for the hundreth time. Three days. Three days and they have yet to so much as move a muscle. He did his best to warm them up, get them to a conscious state, but they hadn't moved a voluntary muscle yet. He glanced at his watch warily, noting that they were rapidly honing in on the seventy-hour mark.  
If they didn't wake up soon to at least drink some water, they would soon be in danger.  
And he didn't want that.  
Subconciously his right forefinger knuckle flew to his mouth and he bit down hard, chewing on the bone absent-mindedly. He had never felt so nervous before. Here, before him, lay the golden egg to his research, and it was quickly slipping through his finger.  
Curious, he glanced at the unconscious form, and poked at their fleshy shoulder. Even hiding under the thin cloth of their tee shirt, it was so soft and squishy in comparison to his bony hands, and he longed to explore more. But no. He wanted responses, movement, information. None of that would do if they just laid there. Still, he poked the shoulder again, and his hand recoiled as if he had brushed against something hot.  
It _moved._  
Gaster watched in fascination as a low, pained groan emanated from the human's mouth, their eyes blinking once, twice...slowly coming into vision.  
Then they bolted upright with a loud shout of surprise, leaning away from the imposing skeleton.  
"AH!!" Gaster recoiled in response, more surprised than anything. They both stared at each other for a wild moment before catching their breath. Gaster straightened first, feeling a slight flush of shame cross his cheekbones. "Th-there's no need for any of THAT now!" He smoothed his wrinkled jacket with a swift pat and sighed deeply, more for his nerves than anything else.  
The human tilted their head, long, thick, hair cascading over their shoulder in a way that made him feel slightly uncomfortable. Then they looked around with wide, curious eyes, trying to get some understanding of where they were and what had happened.  
"Uhm - " Gaster forced his voice to remain even. "You passed out in the cold, so I brought you to my lab..." His voice trailed as they stared at him. They seemed afraid, but also...tired? Their expression twisted, and he was completely taken aback when they hiccuped and started crying, deeply.  
"Oh, none of that now, none of that!" Gaster rushed forward, his movements swift and calculated. The human paused as a water bottle was plopped gently into their hands. "You're dehydrated as it is, we can't have you losing anymore fluids."  
Weakly, with fumbling hands, they attempted to open the bottle. Not once, not twice, but three times their hands slipped, before Gaster gently took it and opened it for them. "Here."  
They looked at him again, shuddering slightly at his appearance, but eager to soothe their dry throat with the water.  
"Drink slowly." He advised, watching them with a careful eye. "Good...good."  
After a moment of gathering their bearings, they gave him another odd look.  
"Thank you."  
Gaster paused. The voice was tiny and somewhat shrill, not to mention hesitant.  
"...You're welcome." He replied calmly. "You're very welcome. Do you feel like eating?"  
They shook their head, slowly.

Recovery takes time, Gaster repeated to himself for what felt like the millionth time over. A few days of slowly working up their appetite and getting them hydrated was paying off, it was just all the damn WAITING.  
They were right there, and he was holding back.  
Magic itched on the inside of his skull, his thirst for knowledge begging him to fudge the formalities at this point and just dive right into the main events. But some form of base instinct told him that wasn't the right thing to do, it wasn't the way to get what he wanted.  
He inhaled deeply, pushing open the door to the recovery room with confidence. "Oh." He froze, surprised to find that the human was standing up and walking around, exploring the room with eagerness.  
"Gaster!" They cried out loud, their head turning towards him. "Hi!" The smile that beamed in his direction wasn't entirely expected, and he shifted his weight.  
"H-hello." His tongue felt stuck behind his teeth as he spoke. Why couldn't he just calm down??  
The shirt she was wearing was thinner than the blankets he was used to seeing them under, and with the cloth forming to their form, he made a discovery.  
"I apologize if this is forward, but...are you...female?"  
They blinked, giving him a blank stare. "Um...yes?" She shrugged, looking down on herself as if realizing for the first time she was only in sweatpants and a thin shirt. "Oh. I guess I have been buried under blankets."  
"Y-yes." He retrieved a flipbook from his pocket, and jotted down some notes.  
"Are you writing about me?" Wide, curious eyes bounded over to him, and she stood on her toes to try to peek.  
He raised the notebook reflexively. "Uh - yes. Yes I am."  
"...Why?" She drew back, just a little, the tiniest hint of fear playing at her features.  
"Oh, well that I can answer. I'm the Royal Scientist of the Underground. My job is to...gather information, and study things." His face fell. "And we know very little about humans." He seemed deep in thought for a moment, and neither of them said anything. Then, perking up as quickly as he had turned solemn, he asked a question of his own. "How did you get down here?"  
She frowned, her eyes glancing at the floor. "I...I had a fight with someone...while we were walking. I tripped and fell."  
"That is...unfortunate." He strained at the word.  
"But not for you, right?"  
"...Sorry?"  
"I-I mean, I gotta be like...worth something to you, right?"  
"I - " He flinched. He had not expected her to refer to herself in such a way. It seemed...degrading? She was right of course, but to be so bold about it out loud. "O-of course. And I mean that in the most respectful way!" He felt himself twinge with embarassment. What was going on?  
"Are you all right?" She asked, concern tinting her voice.  
"Fine, just a little...flustered." He admitted with a relaxing sigh. "I apologize. I was not expecting this situation to affect me so."  
She giggled. "It's all right. I have a tendency to catch people off-balance, even on the surface." The smile she gave was comforting, and he visibly relaxed. "So, why do you wanna know about humans?"  
"Ah - " He flipped through his notebook. "Mostly we want to understand them - you." He corrected, tilting his skull to indicate her specificaly. "Them as a whole, but I mean - you know what I mean. If we can understand you, then maybe one day...we could go back."  
"You want to return?" Her eyes widened in realization.  
"Yes, exactly! But we do not want a repeat of last time...from what I understand."  
"I- I see." She shivered subconsciously. "Uh...l-let me know how I can help, okay?"  
Gaster's soul pounded harshly against his chest. He felt a thrilling rush thrum against his bones, and his excitement was hardly uncontainable. "Really?"  
At seeing just HOW excited the strange skeleton doctor grew at the prospect of doing...Lord knows what to her, she almost regretted it. But he had been kind, sheltering, and caring...and it was kind of his job. "S-sure. Why not? I mean, I'm not a doctor or anything, but I can answer a lot of questions I bet, and stuff."  
Instantly, he turned towards a desk and dug out a clipboard and much larger notepad. Then he dragged the chair over, sitting down and eagerly holding his pen to the paper. "So tell me - "

The questions lasted DAYS. Some made her giggle in amusement. Others made her flush in embarrassment. And some just made her cock an eyebrow. Once he asked to take blood, and she squirmed uncomfortably at the idea, but decided that was a pretty normal thing to do. Watching him flip through the medical 'how-to' book didn't inspire much confidence, but he reassured he was just reading up on human veins. He had taken monster blood several times from several different species, and this was simply a new species that he hadn't much practice with.  
He was so practiced with the needle she barely felt it.  
She stared incredulously as he removed the glinting needle with practiced movements, not letting even a drop of blood seep from the vein as he bandaged the area. "Thank you!" He grinned excitedly. "This will help quite a bit."  
"Sure you got enough?" She said jokingly. He must have taken at least five vials.  
He paused uncomfortably. "I hope so. But I won't take more than that for now." And promptly shoved a cookie in her hands. "Now eat this." And with a pat of her head, his lab coat swung around elegantly as he returned to his work.  
She watched blandly as he swiveled to leave, feeling...oddly empty? "Gaster?" Her voice trembled slightly.  
Curious, he turned back with a wondering expression. "...Yes?"  
She suddenly felt tongue-tied. "Is there anything else I can help you with today?"  
The lights in Gaster's eye sockets constricted to slight pinpricks, barely noticeable. "I - " He paused, his brain working overtime to think of something to day. "You've done quite a bit lately. I'm truly thankful."  
She stared up from the seat. He was standing, stoic as anything, back straight as an arrow. One hand naturally landed over his chest, further displaying how his hands expressed as much as his words.  
"What happened to your hands?" The question was tentative and slow.  
He seemed startled, his sockets going completely dim.  
"And...you...you know you have a crack in your skull...right?" Worry overcame her voice and face.  
His face fell about half an inch.  
"...I'm sorry. I shouldn't have - I'll go to my room - " She turned to leave quietly.  
"They don't hurt anymore." He assured with a steady voice. "I have survived many accidents in this lab. And you give up some things for the sake of - of what you're after." His left hand traced the gap in his right hand subconciously. "But I assure you, I have no regrets in my decisions."  
She turned back to face him. "...I see. I'm sorry for being invasive."  
He chuckled lightly. "Invasive?? You just let me take eight vials of your blood!" His head tilted slightly, his expression grateful. "I'd say it was a fair trade."  
He smiled widely. He really did appreciate the help. He was so innocently grateful, so appreciative of the answers to his prodding questions and requests.  
"Gaster...I'm glad you came and found me." She admitted sheepishly, feeling a slight blush grace her cheeks.  
He was left speechless, staring at her disappearing form.  
"I'll see you at dinner!" She called, not turning back as her feet pounded against the floor in a rush to leave.  
He just stared at the empty air after she was long gone, an unfamiliar buzzing ringing in his head, the aftermath of the somersault his soul had performed in his chest when she thanked him. He ground a finger between his teeth, biting harshly with a hiss. Was he so excited about this research...?

 

Time passed. It was hard to say how many 'days' it was, Gaster counted everything by the hour all the time, and he did so in 72-hours cycles, so time lost a bit of meaning after awhile.  
"Is it morning yet?" She asked lazily once, stumbling into the kitchen in a bathrobe, bleary eyed and hair sticking up on all ends.  
"No. Middle of the night. Go back to sleep." He said cooly, now used to the once-in-awhile intrusions. He listened to her groan with a chuckle as he returned to his samples and notes.  
After a while, he asked why the sleep schedule was so important, and she confusedly tried to explain the concept of an 'internal clock'.  
He was writing notes faster than ever, and they had to stop when his questions contained more jargon than words she recognize. He was disappointed. She apologized, but he kindly told her it was all right, and there was no helping it.  
"If we come across a roadblock, we will simply turn around and take another path." He chimed wisely, not letting the one mystery get him down. He had already unlocked so many others.  
"M'kay." She agreed, munching on a meal in a take-out box. "So what's the next path."  
"Anatomy." He said with a smile, and she nearly choked on her food.  
"...Is something wrong?" He asked in alarm, moving to help her if need be.  
"N-no - " She gasped, holding her hand out to him. "I'm all right." She coughed a bit, and he waited for her to settle.  
"I-I'm sorry, by 'anatomy'..."  
"Well I would like to explore you body, of course." He started, launching into a ramble as he flipped through a folder. "I've had very little experience with actual human contact, and my books are...well, just books. Reading can only do so much. It would be strictly for research purposes, of course, so there's no need to get...flustered..." His white skull tilted up, his words slowing to a halt when he saw she was stock still, staring at her food as a bead of sweat trickled down her face. "...Is that not all right?"  
She coughed, hard. "W-well if you need the information..." She grimaced. She certainly felt like helping the odd skeleton monster, but this... "I-it's all right." She decided, and he could hardly hold back his grin.  
"You're certain?" Uh-oh. She knew that tone. He was anxious for this one, like it was something he'd been waiting a lifetime for.  
She inwardly cringed. It meant that much to him, and he had been nothing but a gentleman, and kind, and sweet...she flushed. Maybe she was nervous for an entirely different reason. "Yeah, I'm sure." She turned slightly, trying to shrug off her embarrassment, but the heat was settling in her cheeks quickly. "U-um...when...?"  
"When would be okay?" He seemed very puzzled at the 'when', as if it wouldn't matter at all.  
She bit her lip. She debated tomorrow, but realized it would be hell to get to sleep tonight with this weighing on her mind. No, best to get it done and over with now that she's agreed. "H-how bout tonight? Just give me a bit, okay?"  
"Tonight?!" He nearly jumped from his seat with a gasp. "Surely!"  
Her embarrassment receded and she chuckled as she watched his hands ball into excited fists at his side. He really couldn't help himself.  
"I'll get things ready!!" He announced loudly, shooting out of the room, hands waving crazily.  
She sighed deeply. "Me too, I guess..." Her food suddenly unappetizing, she boxed the leftovers and dropped them off in the kitchen.  
The shower was warm against her skin, and she gave herself a thorough washing. If Gaster wanted a human body to look at, by GOD was she going to give him something to look at! She finished up quicker than expected, and hesitantly slipped out of the shower to dry off.  
Her bathrobe was thick and fluffy, and she sank deep into it with a content sigh. "Okay, no biggie." She told herself, but the blood was already rushing in her ears, her heart pounding roughly against her ribcage. "Ooookay." She forced a grin and made her way down the winding hallways to the lab.  
"Gaster...?" She called, hesitant, when she didn't see him in the room she expected. "Gaster??" Her voice echoed, bouncing off the metal walls easily, though shortly.  
She gripped the bathrobe tightly around her, her squishy feet cold against the slick flooring. "Gaster - oh." She paused in front of a clear glass room, forcing a smile as he waved her in eagerly.  
She pushed the door open, earning excited noises from the tall skeleton. "Are you prepared?" He asked politely, and she just nodded.  
"Y-yup."  
"No need to be nervous!" His hands hardly pausing as the waved about with his words effortlessly. She giggled, feeling some of her embarrassment melting away. "I'm just wanting to document how you look, feel...that sort of thing. If I hurt you, at all, let me know, all right?"  
She nodded stiffly. Somehow, despite the embarrassing situation, she did feel entirely safe in his hands.  
"Good!" He said, pleased. There was a snapping sound of bone on bone, and six separate disembodied hands appeared.  
"Y-you're using those?" She asked, shoulders hiking in sudden nervousness.  
Gaster's smile faltered slightly. "...Just to help. Things will go quicker." He soothed, and gestured towards her with his own hands as the disembodied ones slowly slid off her bathrobe.  
Carefully, she sucked in a breath, holding her head high, and led to lay stomach down on the observation cot that was prepared. Gaster had covered it with a thick blanket, completely aware that the cold metal would be uncomfortable and counter beneficial to the entire process.  
"Now I'm just going to observe your spinal areas." He said firmly. His tone was sterile, completely absorbed in the task at hand.  
She exhaled slowly. That made this quite a bit easier and much more bearable.  
That didn't make the first touch any less jolting. The chalky texture of bone on skin was unfamiliar. Lord knows how long she was down here, but she and Gaster barely had any actual physical contact unless it had to do with observing dilating eyes, or taking a vial of blood. But this...  
The hand ran down her spine slowly, acting like it was memorizing every dip and cranny in the skin. "Interesting..." She heard him mutter, then the sound of charcoal scratching at paper.  
Her hands clenched underneath her. Her breath hitched. All her senses suddenly flared to life with hyper sensitivity, and she felt her face grow hot against her will.  
With another jolt, a second floating hand joined the first, rubbing at her side to trace the ribs that slid under her skin.  
It was painfully slow. They searched thoroughly, taking note of every spot, every divet, drinking in any detail they would come across as Gaster scribbled non-stop at the desk.  
She held her breath as they moved low to her ass, and gave her self-proclaimed bubble butt a light squeeze.  
"...Huh." More scribbles.  
Her face was hot. This was more than she had anticipated.  
Third and fourth hands moved up and down her legs, but not for too long, before she heard him speak -  
"Could you turn around please?"  
She was expecting it, but was far from ready for it. Her breath caught in her throat, and she swallowed hard, forcing her discomfort down to the pit of her stomach. It was just. For. Research. She was helping me. She wanted to help him. She berated herself for being so flustered, she had grown to respect and maybe even admire the gentlemanly skeleton monster named Gaster. He wasn't going to hurt her, and even knowing that...something else made her heart pound faster, made the flush creep up the back of her neck all the way up to her ears.  
Slowly, she moved one arm out from underneath her breasts to push herself to roll over. She FORCED her arms to remain at her side, knowing Gaster would be interested in her fleshy bust.  
The hands traced her collarbones first, taking special note to how they connected to her neck. One hand tipped her chin up gently, and she felt a shiver that wasn't from any kind of chill creep down her spine.  
"...Are you all right?"  
"F-fine!" She bit evenly. Giving him a reassuring look before he continued. Not before taking a note, of course. She felt the heat on her face spread. Why did she get the sudden urge to - ?  
Her thought was drowned when a hand flicked across her breast, taking special interest in the nipple that instantly hardened under the touch.  
There was no helping it now. "Hnnn~~" The hands raised, and Gaster instantly looked up at his subject, the lights of his eyes flicking between her and the notes he was jotting down as fast as he could.  
"Remember, if I do something wrong - " He reminded carefully.  
She just nodded.  
The hands continued their roaming. They massaged her breasts, which made the subject even more frazzled, and he was trying to figure out what exactly was going on with that. Experimentally, he kept on hand on her breast while the rest fanned out, carefully moving up and down her stomach, memorizing the pattern of her bellybutton and feeling the rippling muscles under the skin. It was easy because she was moving quite a bit, though trying not to.  
Her chest heaved, she struggled to keep her breath even. A tingling scratched at the inside of his skull. What precisely was eliciting such a strong reaction?  
And then one hand ventured to the juncture between her thighs, and she moaned loudly.  
Instantly, the hands were removed and Gaster's startled figure jolted into a standing position. "...Human?"  
The young woman had her eyes closed, her head thrown to the side, hair messily and carelessly splayed across her face. She swore lightly. She hadn't meant to let that out, but after being teased for what felt like forever there was just no stopping it.  
"Ahh...sorry. " She panted.  
'Sorry'? Gaster looked down at the spot that had caused the disruption curiously. With a flick of a wrist, the floating appendages all dispersed in extended magic. He was acting purely on gut instinct, but maybe he should do this part himself. It was practically the final piece, anyway.  
His hand slid down, and he was slightly surprised when her legs parted on their own, allowing him a better view. She didn't say anything.  
Curious, he leaned close, watching the delicate folds as they dripped with a strange liquid. "Fascinating..." He mumbled to himself, carefully rubbing one of his long, bony fingers along the slit, eye lights constricting when he found a curious little ball of flesh concentrated right above. He rubbed it none too gently.  
"GY-!" She stopped herself, and Gaster just stared, eyes focused on the spot as he vaguely realized her legs had begun to quake and shiver under his touch. And...was the liquid getting more dense? It seemed to drip from the source, and he curious slipped one finger past the front folds and was stunned to find the warm, fleshy cavern went fairly deep into the humans body.  
She jolted slightly again, but still made no protests.  
Gaster was honestly trying to get a better look, oblivious to what his rubbing back and forth was doing to the poor young woman. A second bony appendage followed soon after he grew frustrated enough, and he attempted to feel around the area for...well, anything really. At this distance, there was also a strange smell filling his skull, making it buzz with a headiness he was not familiar with at all.  
"G-Gaster- " The human breathed on a squeal, her breath hitching and the burn of tears hitting the corner of her eyes.  
Surprised yet again by the actions of the human, Gaster bolted up, removing his hand and studying the gooey substance with great interest. He smelled it. Scraped a bit off into a readied vial. Then, with little hesitancy, shoved a coated finger in his mouth to taste it.  
It was...different. He concluded, and the fuzzy feeling returned. He glanced at the young woman, feeling heat settle deep in his bones. She was completely red-faced, looking up at him with glazed over eyes and an emotion he had no idea how to pinpoint.  
...But he was quickly finding himself wanting to do nothing more than to touch her again.  
A sly smirk tugged at the corner of her lips. "I saw that."  
"Er..." He was at a loss of words. Was there some significance to what he had just done?  
Her voice was tinted with an unfamiliar tone, and it dropped low, sultry even. "Want more?"  
His soul THUDDED against his ribcage. He felt magic course through his bones like never before, not powerful, but NEEDING to do SOMETHING. If he normally kept saliva in his mouth he was sure it would've gone dry, as he recognized the chalkier than normal sensation in the back of his non existent throat. "...I...I think I do."  
His answer surprised even himself, and he felt an odd tugging in the front of his pants. Ignoring it for now, he returned to the spot between the young woman's legs, purple dusting his cheekbones more heavily with each passing second. He barely felt control any control over his actions at this point, the burning desire in his bones leading his actions almost blindly. His head had never felt so full of cotton before, and he was desperate to do something to help clear it.  
"Y-you can- HNGH!" She had started to tell him, but he was already leaning down, his primal urge moving him forward. Without hesitation, his thick, purple-tinted tongue lolled out, and she gasped in total pleasure as the unbearable warmth spread over her most sensitive spots.  
Gaster recorded every reaction in the back of his mind, making mental notes, but it was getting harder and harder to do. What he wanted right now was to taste and feel whatever it was he was tasting and feeling. He reached deep with his tongue, magic thrumming against him almost painfully. The pants and moans from her spurred him on, making him want to press deeper, to twist more, and completely on instinct, he removed his tongue to lavish the outside areas while two of his long, slender fingers pressed insistently inside.  
She nearly screamed. "GASTER - GASTER -!!" She clawed at the blanket under her, fists and toes clenching tightly. "STOP!" She finally screamed, and bewildered, he backed off, standing up way too quickly with shaky limbs. Being a man of stature, he caught himself before tripping but just barely.  
"Wh-wh-" He couldn't even form a word. Why had she - ? But she was already moving, staring at something between his legs.  
"Want - with you - " She tried to explain, urgency and heat and desire coating her entire existence. Her face was entirely too red to be safe, he concluded. Then he looked down.  
"GAH!" A thick bulge pressed against the fabric of his lab pants, begging to be released. The thrumming of his magic was now nearly unbearable, and he stared in total disbelief as she reached over and easily pulled the pants down just enough to let the thick, purple member spring forward.  
"What's wrong?" She asked with total innocence, looking up at his confused face with worry. "You want to, right?"  
Now, Gaster considered himself a man of knowledge. Pride. And composure. Right now, he felt like he had none of these, and that fact in of itself was enough to make his face burn purple with embarrassment. But then this young female tenderly took this...whatever it was, that appeared before him carefully into her mouth, and he ground his teeth together in shock, one hand flying up to his mouth so he could bite down on the normally abused finger he was so used to chewing on in times of nervousness.  
It felt so good. His magic ebbed and flowed with the rhythm her mouth was creating, and a pulsating need demanding more. The friction was incredible, and then gasped in a heated moan as he recognized the feeling of her tongue bobbing up and down with her mouth...  
His legs shook. He wouldn't be able to stand much longer. His hands had already grabbed something, he wasn't even sure what it was, behind him for support.  
Sensing the issue, she leaned back onto the cot, carefully pulling him with her. He was bewildered.  
"You act like you've never done this before." She giggled.  
It took a moment for his jaw to work. "I-- I haven't." He admitted, but wondering why the hell it hasn't happened before now. "I-" He gestured towards his nether regions. "I don't even know what THIS is!"  
She paused, just a moment. "...Do you want to stop?"  
"God no." The words were on desperate, heated breaths. He didn't even fully realize what he had said until after it was spoken, and before anything else happened she leaned up, crashing her lips into his teeth, and pushing her tongue past them to search out his.  
The surprised gasp was entirely muffled as the rough appendages rubbed together lovingly, both of them enjoying the friction. He relaxed into the kiss, his sockets a little more than half closed as her hand reached down, guiding him to caress the opening.  
Gaster made a strangled cry in realization, but she kept kissing him, her other hand firmly placed on the back of his smooth head. "It's okay." She said with a smile, and he felt his entire skull burn with a radiant heat. Slowly, carefully, experimentally, she helped him inch is way in, both moving slowly as possible to get the feeling.  
"Ohh...oh God..." She moaned, loudly, unable to hold back any more as the length stretched and filled wonderfully.  
She didn't need to help anymore. The primal burning in his soul and bones screamed at his instincts, helping him do things he didn't know he knew how to do, and he quickly started to move, relishing the soft, velvety walls that tightened so wonderfully around him.  
"G-Gaster -" She breathed. She was already so close from before, and it wasn't taking much to push her over the edge. She could feel the heat coming off his now-purple face, he was so enthralled in the moment. Somehow, that made it all the more thrilling for her. "Gast - " She was nearly breathless. "I'm cumming, I'm cumming--!!"  
He had no idea what that meant, but he did manage to observed she was nearly incoherent with lust, focusing only on how good her body felt, and my God if it was anything like what he was feeling he was happy for her.  
Again, instinct took over as he pulled her body close, angling himself a little higher to hit a spot that was fresh, deep in her center, and leaning down to whisper in her ear at the same time, "Then do it." And his tongue rolled lovingly over one of her ears, anything to get her taste in his mouth, he realized.  
Hands gripped at his humerus, too tight to be safe he assumed but the pressure was somehow welcoming. The moan she was letting out was much more like a shout, and she half-screamed, half-panted his name multiple times as her walls squeezed at him almost painfully. The friction was too much. It was like a coil being twisted inside, and suddenly the pressure released and he found himself losing balance, eye sockets flickering into darkness as he gasped for breath and heat completely over took his entire body, his release pouring into her, though he had no idea what that meant, for either of them. The thrumming in his bones calmed, sweet relief filling him at the same moment he hit the height of his pleasure.  
He collapsed, trying to be careful not to crush the fleshy young woman beneath him but she wrapped her arms around his back with a pat of satisfaction. They were both panting heavily, and Gaster realized with shock that he had been sweating profusely.  
His slick bones felt wobbly, and he struggled to sit up.  
"Gast."  
The soft voice had his head turning towards her, and his eyes constricted at the sight of her.  
Eyes half-lidded. Hair a mess, sticking in different areas. Sweat-slicked skin. And a playful smile tugging at her lips. She licked them, her tone still low and sultry.  
"Some research, huh?"  
He couldn't agree more.


End file.
